class Solution {
public boolean isBracket(char ch) {
if('(' == ch || ')' == ch || '{' == ch || '}' == ch
|| '[' == ch || ']' == ch) {
return true;
}
return false;
}
public boolean isValid(String str) {
char[] stack = new char[str.length()];
int top = 0;
//开始遍历字符串str
for (int i = 0;i < str.length();i++) {
if(!isBracket(str.charAt(i))) {
continue;
}else{
if(str.charAt(i)=='(' || str.charAt(i)=='{'
|| str.charAt(i)=='[') {
stack[top++] = str.charAt(i);
}else{//可能是右括号
if(top == 0) {//右括号多
System.out.println("右括号多");
return false;
}
char c = stack[top-1];
if ('(' == c && ')' == str.charAt(i) ||
'{' == c && '}' == str.charAt(i) ||
'[' == c && ']' == str.charAt(i)) {
//匹配了一对出栈
--top;
}else{
System.out.println("右括号次序匹配出错");
return false;
}
}
}
}
if(top > 0) {
System.out.println("左括号比右括号多");
return false;
}
System.out.println("左括号===右括号");
return true;
}
}
